The field of the present invention is centrifugal sifters.
Centrifugal sifters are well known which include an axially tensioned cylindrical screen mounted to a frame. A shaft including an auger along a first portion and paddles along a second portion is rotatably mounted within the frame with the paddles extending axially through the cylindrical screen. The shaft is driven by a motor. An inlet manifold delivers material to be separated to the auger. A first outlet manifold collects the sifted material from about the cylindrical screen. A second outlet manifold to one end of the cylindrical screen collects the material not sifted through the screen.
The cylindrical screen is mounted on short cylindrical flanges at either end. Clamp bands are typically positioned about the screen over the flanges and tightened. One of the mounting flanges is fixed to the frame while the other is mechanically drawn away from the first so as to tension the screens.
Difficulties can arise with the inappropriate mounting and tensioning of such cylindrical screens using clamp bands and a rigid tensioning mechanism. The paddles rotate rapidly within the cylindrical screen so as to generate pressure waves for enhancing sifting through the screen. Forces are in turn generated on the screen mounting mechanisms. Further, rigid tensioning of the screens can also result in a significant load on the mounting mechanisms. The screens also tend to axially elongate during use. A loss of tension in the cylindrical screen from such conditions can result which can in turn result in wear and failure of the screens.